Search PubMed⌕ Search

Biomedical subjects

Z Ali

Publications and source records attributed to Z Ali.

At least 91 records · Page 5Linked to original sources
PubMed1990

Region-specific recombination and expression are directed by portions of the Drosophila engrailed promoter.

The Drosophila engrailed gene is expressed in the cells of the posterior developmental compartments. To investigate how the engrailed gene is regulated, chimeric genes consisting of fragments of the engrailed promoter and Escherichia coli lacZ were incorporated into the Drosophila germ line by P-element-mediated recombination. Fusion constructs with 7.5 kb of 5'-flanking sequence contain sufficient information to promote expression in most of the embryonic, larval, and imaginal posterior compartments; transformants with smaller fragments of the 5' region do not. Remarkably, of 20 independent transformants with constructs containing more than 1 kb of 5'-flanking DNA, 7 integrated in or around the engrailed locus. These strains inactivate engrailed function to varying degrees, and some express lacZ with a position- and temporal-specific program that is indistinguishable from the normal engrailed gene. Presumably, in these strains, lacZ is expressed in the context of the engrailed promoter.

Animals↗
PubMed1990

Occurrence of diabetes mellitus after gestational diabetes mellitus in Trinidad.

We undertook this study to determine the incidence of diabetes mellitus (DM) and impaired glucose tolerance (IGT) after gestational diabetes mellitus (GDM). It is a follow-up study of a consecutive sample of women with GDM in a tertiary care center in Trinidad, West Indies. The cohort was a consecutive sample of 157 women with GDM who delivered in the hospital between June 1981 and December 1984. Of these, a volunteer sample of 60 women (38%) consented to participate 3.5-6.5 yr later. The two groups were remarkably similar in ethnic composition, mean age at index delivery, marital status, and family history of DM. Interviews revealed that 26 women (43%) had already developed DM for which they were receiving treatment. The remaining 34 women (57%) were given a 2-h 75-g oral glucose tolerance test, and fasting and half-hourly venous blood samples were obtained and analyzed for plasma glucose. Based on accepted diagnostic criteria, 11 (32%) of 34 had DM, 10 (29%) had IGT, and 13 (38%) had normal glucose tolerance. A total of 37 (62%) of 60 women had developed DM, and another 10 (17%) had IGT in the intervening 3.5-6.5 yr. The results support findings that GDM is associated with an increased risk of mothers developing DM in later life.

Diabetes Mellitus↗
PubMed1989

A review of 36 babies with necrotizing enterocolitis.

The clinical features, management, and outcome of 36 babies with necrotizing enterocolitis seen over 5 years at the Neonatal Unit, Mount Hope Women's Hospital, Trinidad, are described. The crude overall mortality rate was 25 per cent. The results suggest that prematurity, sepsis, and umbilical catheterization, but not enteral feeding or polycythaemia may be involved in the aetiology of this disease.

Combined Modality Therapy↗
PubMed1989

The extent of small fibre sensory neuropathy in diabetics with plantar foot ulceration.

Thresholds for cutaneous warming and cooling stimuli were measured in 20 diabetics with neuropathic foot ulcers. All patients had a profound disturbance of sensory perception in the ulcerated foot with complete loss of perception of warming; thresholds for vibration and cooling were highly abnormal in all but two patients. Measurements of thermal threshold were made on both feet in 10 patients: warming was lost bilaterally in all, and cooling was bilaterally absent in six. There was no clear pattern of sensory loss in those diabetics with unilateral foot ulceration to suggest that sensory impairment was the determining factor for the development of a plantar ulcer. Measurements of thermal thresholds were made at additional sites in 13 patients and although the most marked abnormalities of sensation were always found in the feet, in some severe neuropaths, abnormal thresholds on the hand and even the face were demonstrated. Thresholds for warming were invariably more abnormal than thresholds for cooling. The diabetics with neuropathic ulceration in this study all had severe generalised peripheral nerve disease involving large myelinated as well as both small myelinated and unmyelinated sensory fibres. The quantitative evidence on the distribution of sensory loss for thermal sensations supports the hypothesis that the neuropathic process affecting the small myelinated and unmyelinated fibres is length dependent.

Adult↗
PubMed1989

Patterns of engrailed protein in early Drosophila embryos.

By the onset of gastrulation during nuclear cycle 14 of Drosophila embryogenesis, the engrailed gene is expressed in fourteen one-cell-wide stripes. Each stripe defines the anlagen of the posterior compartment of a metameric segment. We report here several observations relating to the role and disposition of the engrailed protein during the embryonic stages that precede cellularization. We demonstrate that in embryos mutant for the engrailed gene, there were characteristic morphological abnormalities as early as the 6th cleavage cycle. In addition, the engrailed protein was detected in pre-cycle-9 embryos by Western blot analysis. When localization of engrailed protein begins during cycle 14, engrailed expression was first present in broad anterior and posterior regions before the fourteen-stripe pattern appeared.

Animals↗
PubMed1988

The value of testing for unmyelinated fibre, sensory neuropathy in diabetic impotence.

Measurement of thermal thresholds provides a means of assessing neurological deficit and in particular of recognising a neuropathic process affecting unmyelinated and small myelinated fibres of the peripheral nerve. These groups of fibres cannot be tested by nerve conduction studies but are particularly susceptible to disease in diabetes. Thresholds for thermal sensation on the sole of the foot were measured in 33 men presenting with erectile dysfunction. All 15 men with erectile dysfunction, which had been considered on clinical grounds to be neuropathic, had abnormal thermal thresholds. Diabetics with non-neuropathic erectile dysfunction had normal results. Whereas tests of unmyelinated sensory fibre function were abnormal in all those with neuropathic erectile dysfunction, electrophysiological measurement of the bulbocavernosus reflex was normal in five of nine men with diabetic neuropathic impotence.

Adult↗
PubMed1988

The conduction velocities of peripheral nerve fibres conveying sensations of warming and cooling.

With the current practice of measuring thresholds for warming and cooling separately, the question of the exact nature of afferents subserving these sensations assumes new importance. Experiments to measure reaction times to warming and cooling stimuli at two sites on the lower limb are described. The conduction velocity for each sensation was estimated from the conduction distance and conduction time in the limb. The estimated mean conduction velocity for warming was 0.5, SD 0.2 m/s and cooling 2.1, SD 0.8 m/s. These figures confirm that the sensation of warming is conveyed in unmyelinated and cooling in small myelinated peripheral nerve fibres.

Adult↗
PubMed1987

Binding of linker histones to the core nucleosome.

Binding of chicken erythrocyte linker histones H1/H5 to the core nucleosome has been studied. Histones H1/H5 bind very efficiently to the isolated core nucleosome in vitro. The binding of linker histones to the core nucleosome is associated with aggregation of the particles. Approximately one molecule of linker histone binds per core nucleosome in the aggregates, irrespective of the concentration of the linker histones and the salt used. Histone H5 shows greater binding affinity to the core nucleosome as compared to H1. The carboxyl-terminal fragment of the linker histones binds strongly to the core nucleosome while the binding of the central globular domain is weak. Each core nucleosome is capable of binding two molecules of carboxyl-terminal fragment of linker histone. The core nucleosome containing one molecule of carboxyl-terminal fragment of linker histone requires higher salt concentration for aggregation while the core nucleosome containing two molecules of carboxyl-terminal fragment of linker histone can self-associate even at lower salt concentrations. On the basis of these results we are proposing a novel mechanism for the condensation of chromatin by linker histones and other related phenomena.

Animals↗
PubMed1987

The transcription unit of the Drosophila engrailed locus: an unusually small portion of a 70,000 bp gene.

Transcripts from the engrailed gene of Drosophila melanogaster have been characterized by Northern, S1 nuclease sensitivity, and primer extension analyses. The engrailed gene encodes three poly(A)+ transcripts (3.6 kb, 2.7 kb, and 1.4 kb) that derive from a 3.9-kb portion of the genome. No other transcribed regions were found up to 16 kb downstream and 48 kb upstream of the engrailed transcription unit, the portion of the genome to which engrailed mutations have been mapped. The structures of the engrailed transcripts are unaffected by lethal engrailed mutations that break the locus at points in the transcriptionally silent regions. Transcripts expressed by 145 kb of DNA that surround the engrailed locus were also identified by Northern analysis. In contrast to the large portion of the engrailed gene that is transcriptionally inactive, most of the surrounding regions are 10-fold more densely populated with transcripts. We presume that the unusually large silent region at the periphery of the engrailed transcription unit signify the presence of special mechanisms that regulate its expression.

Animals↗
PubMed1987

Placebo-controlled, double-blind evaluation of the efficacy and safety of yellow mercuric oxide in suppression of eyelid infections.

We tested an over-the-counter ophthalmic ointment, yellow mercuric oxide 1%, for safety and efficacy in decreasing eyelid-margin bacterial-colony counts. Of 150 patients screened for high bacterial levels, 78 were randomized in double-blind fashion to either yellow mercuric oxide bid (41 patients or 53%) or a placebo (37 patients or 47%). Bacterial-colony counts were determined at outset and at days 4 and 7 of treatment. At the conclusion of treatment on day 7, 87% of patients in the mercuric oxide group were successful in decreasing bacterial counts, compared with 59% of patients treated with placebo (P = .01). Side effects were no higher in the active group than in the placebo group. We have shown mercuric oxide 1% to be safe and effective in reducing eyelid bacterial-colony counts in patients with hordeolum and blepharitis.

Adult↗